Identification of Proteins Isolated by 2-D Gel Electrophoresis Using Capillary Zone Electrophoresis and Matrix-Asisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry The goal of our project is to combine capillary zone electrophoresis (CZE) fractionation of protein tryptic digests with matrix assisted laser desorption ionization time-of-flight (MALDI-TOF), peptide mass database searching and high energy collision induced dissociation (CID) sequence analysis for the identification of proteins isolated by 2-D gel electrophoresis. The ability to analyze thermally labile and nonvolatile species, short analysis times and sample consumption in the low femtomole range are striking features of CZE. These advantages are also inherent in MALDI-TOF mass spectrometry. With the additional ability to mass detect, coupling CZE with MALDI-TOF would provide an extremely powerful technique for determining peptide masses especially in instances when samples are limited. Such is the case when trying to identify 2-D gel separated proteins by analyzing their tryptic peptides.